This application requests partial support for an International Register Workshop for Inherited Metabolic Disorders, to be held October 5, 1991, as a pre-satellite meeting to the 8th International Congress of Human Genetics, Washington,D.C. The purpose of the workshop is to bring together national and international experts and interested professionals in inborn errors of metabolism to begin to determine the infrastructure needed for: [1] an international exchange of information on inborn errors of metabolism [IEM]; and [2] an IEM international data collection system(s) for these disorders. The primary focus of such a Register is to serve as an information resource and retrieval system to investigators researching selected inborn errors of metabolism. Limited availability of patients for research studies is a major problem for rare disease investigators. Because most rare disorders have low incidences, the number of cases is small, even at large medical centers or at a regional or national level. An international Register of interrelated entries linking physicians, cases and disorders can facilitate the organization of these data so that experience can be gathered, collated and shared more efficiently. An International Register Feasability meeting held in San Francisco May 29, 1990, attended by invited a professionals from abroad and from the United States, recommended active exploration into implementation of an International Register of Inherited Metabolic Disorders. An Executive Planning Committee has been established to organize and plan for the Workshop [Drs. Buist, Holton, Levy, McCabe, Meaney, Mize, and Scriver]. Drs. Charles R. Scriver and Harvey L. Levy will give keynote addresses focusing respectively on: [1] International Experience and Registers: Principles and Practices for the Future, and [2] The Importance of an International Register in Enhancing the Value of Newborn Screening. Two round-table discussion sessions will be held, each covering topics minimally designed to encompass: [1] Ascertainment Sources: Physicians, Newborn Screening Programs, Patients/Parents, and other Databases; [2] Disorder Selection; [3] Data Items Important to a Register; [4] Information on the Natural History of Disorders; [5] Monitoring Incidence, Prevalence, and Geographic Clustering of Cases; and [6] Research and Education Objectives. A total of 65 invitees and self-selected participants will attend the Workshop. A Workshop monograph will be written as an initial working document for a Register implementation.